====================================================================== IBIS INTERCONNECT TASK GROUP http://www.ibis.org/interconnect_wip/ Mailing list: ibis-interconnect@freelists.org Archives at http://www.freelists.org/archive/ibis-interconn/ ====================================================================== Attendees from August 2 Meeting (* means attended at least using audio) ANSYS Curtis Clark Cadence Design Systems Bradley Brim Cisco David Siadat Intel Corp. Michael Mirmak Keysight Technologies Radek Biernacki, Ming Yan Mentor, A Siemens Company Arpad Muranyi* Micron Technology Justin Butterfield*, Randy Wolff* SAE ITC Maureen Lemankiewicz, Logen Johnson Signal Integrity Software Walter Katz, Mike LaBonte* Teraspeed Labs Bob Ross* University of Aveiro in Portugal Wael Dghais Mike LaBonte convened the meeting. No patents were declared. Justin Butterfield took minutes. Review of Minutes: - Mike called for review of the minutes from the July 26 meeting. Bob Ross moved to approve the minutes. Randy Wolff seconded. The minutes were approved without objection. Review of ARs: - Mike to update the BIRD189.5 draft 4 and send it out to mailing list. - This is done. Opens: - None BIRD189.5 draft 4: Mike showed the edit Bob had suggested on page 10, in regards to removing the line limit from the [Description] in [Define Package Model]. Bob asked if this change should be at the end of the BIRD. Mike replied he added it on page 10 to keep the changes in page order of the IBIS specification, but said he would move the text to the end of BIRD189.5. Mike noted that Arpad Muranyi still had a question on Example 6. Arpad stated that one of the issues is related to the pins G1-G4, which are individually connected on terminal lines 9-12, and how this relates to the [Pin Mapping]. Randy pointed out that the [Pin Mapping] is at the die side, while this example is defining the Pin_rail. Arpad asked about the terminal lines 6-8 which are connected to pad_rail. Bob mentioned we don't know how the power and grounds are connected inside the subckt. Arpad stated the real issue is with the VSS which is connected by signal_name. Randy asked if the reference should be to VSS1 or VSS2. We are splitting the VSS into VSS1 and VSS2 with the [Die Supply Pads], which defines VSS1 and VSS2. VSS1 and VSS2 could be separate pads on the die. Arpad asked about terminal line 11 in Example 6 which implies that the 4 VSS terminals are shorted, while lines 9-12 create separate connections. Mike replied that these [Interconnect Model]s connect together together making a complete connections between pins, pads and buffers. He thought the main issue is when signal_name is used to make the connection. Randy asked if the terminal line 11, VSS reference, made sense to have. Arpad agreed that this line did not make sense to him. Mike thought this line is the reference which might connect capacitors inside the ISS subckt. Arpad suggested the example could be more specific where the reference is connected. Mike noticed that Buffer_Rail and Pin_Rail were swapped due to the recent change that was made to the BIRD. Randy suggested to have 2 references to each VSS1 and VSS2. Mike changed the example to reflect this. Mike asked, if signal_name does not make sense to use, then possibly the BIRD should have a rule to prevent this. He pointed out when signal_name is used the EDA tool does not know which node to connect to. Bob thought that the tool needs to figure this out. Arpad stated that the tool needs to have the information to connect the model or the IBIS specification has an issue. Mike thought if signal_name is used, then there is a short from the pin to pad or pad to buffer. Bob mentioned he has a presentation on mismatched interfaces. He has cases which are legal in the syntax but don't make sense. Arpad stated that this is a common issue in programming where code will follow the syntax rules without giving errors but still gives incorrect results. Mike asked about the unused_port_termination issue that is still remaining. Arpad stated that there is a proposal to delete the unused_port_termination. There still is the issue of referencing. Mike will send out BIRD189.5 draft 5. Arpad moved to adjourn. Randy seconded. The meeting adjourned without objection.